The focus of this study was on the comparative analysis in the area of illustrations between the primary school from third grade to the sixth grade between Korean and American science textbooks in order to offer some suggestions for consideration of the Korean science textbooks, which will be revised in 2009. The results are as follows: The number of illustrations per page in Korean science textbooks are more than that of American science textbooks. As the type of illustrations, the ratio of photos is the highest and as the role of illustrations, data provision has the highest percentage in both countries. The motivation role in Korean science textbooks seem to be higher than American science textbook, whereas study summary role is more prominent in American textbooks than in Korean textbooks.